HDMI

High Definition Multimedia Interface

The nearly standard interface on an HDTV, it can pass both digital audio and video and can also incorporate HDCP DRM for protecting content.

ATI graphics cards

Good support, mostly used DVI-HDMI cable to connect HDTV. Don't forget setup Underscan to remove black borders. Can be set that in /home/mythtv/.xinitrc:

/opt/bin/aticonfig --set-dispattrib=tmds2i,positionX:0
/opt/bin/aticonfig --set-dispattrib=tmds2i,positionY:0
/opt/bin/aticonfig --set-dispattrib=tmds2i,sizeX:1920
/opt/bin/aticonfig --set-dispattrib=tmds2i,sizeY:1080